[Cake] Using cake to shape 1000’s of users.

Jonathan Morton chromatix99 at gmail.com
Sat Jul 28 12:11:05 EDT 2018

> On 28 Jul, 2018, at 6:51 pm, Dave Taht <dave.taht at gmail.com> wrote:
> That's also pretty low end. On the high end nowadays there's stuff like this:
> https://www.amazon.com/Intel-Xeon-E5-2698-Hexadeca-core-Processor/dp/B00PDD1QES

Intel is no longer high-end for x86 CPUs.  Not all of the market has realised that yet, but it's true.

Look at Threadripper 2 which scales up to 32 cores, 64 threads in a single socket at HEDT prices, and EPYC which just goes bonkers in terms of I/O capabilities and still costs less than its nearest Intel competitor.  None of which has any serious concerns with the recent series of Meltdown/Spectre speculation bugs, unlike Intel.

AMD is moving to a 7nm silicon process which apparently works pretty well already, and is theoretically on par with Intel's 10nm process which they still haven't got working reliably after how many years of delays now?  And they're already beating Intel over the head with a 14nm process which is theoretically *inferior* to Intel's 14nm process, which they'll be stuck with in practice for *at least* the next year even by their own wildly optimistic latest estimates.

The only place Intel temporarily holds a real advantage is in maximum single-threaded turbo clock speed.  This is relevant to a shrinking minority of users these days.  AMD's next CPUs are supposed to make that wholly irrelevant with a significant further jump in IPC - because they were designed to compete with 10nm Intel CPUs that Intel now looks very unlikely to be capable of manufacturing.

And is this relevant to "Super Mega Turbo Cake Edition XLRi"?  Well, one of the nice things about having lots of users is that you can statistically multiplex them across multiple hardware queues more easily.  Each subscriber's traffic can sanely end up on the same queue each time, and each queue can have a separate "Super Cake" instance allocated an even division of the total backhaul bandwidth, and in theory each of *those* can run on its own CPU core.  Instant throughput boost.

 - Jonathan Morton

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